Guide means for inner cutter of a dry shaver



`[une 29, 1965 D. R.v LOCKE? GUIDE MEANS FOR INNER: 01mm oF A DRY' smwER III,

1N VENTOR. 7A WD Ki 06K! United States latentA 3,191,300 GUIDE MEANS FOR INNER CUTTER F A DRY SHAVER David R. Locke, Bridgeport, Conn., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed Jan. 14, 1963, Ser. No. 251,356 Claims. (Cl. Sil-43.92)

This invention relates to guide means for a movable cutter of an electric dry shaver cutter head.

In the cutter heads of some electric dry shavers there is provided a movable metal inner cutter disposed `within a stationary metal outer cutter and which cutters cooperate to shear facial hairs that enter aligned openings in the cutter elements. The inner cutter is connected to a drive member such as the motor drive shaft, oscillator arm or the like which move the inner cutter within the outer cutter. Cutting surfaces of each cutter element have portions contacting one another during operation of the shaver and clearances are provided between other portions of the inner cutter and the inner walls of the outer cutter. A problem inherent in the construction Iof electric dry Shavers is the contact of the latter surfaces of the inner cutter with the inner sidewalls of the outer cutter during operation of the shaver. Contact of the latter portions is caused by lateral shifting of the inner cutter on the drive member which results in undesired and excessive noise and possible pinching of facial hairs from the skin rather than eecting the desired shearing thereof.

It is an object of the present invention to provide novel cutter guide means for an electric dry shaver cutter head.

Another object of the present invention is to provide novel cutter guide means for an `electric dry shaver cutter head having a stationary cutter and a movable cutter and which means positively prevents lateral shifting of the movable cutter from its intended path of movement during `operation of the shaver.

'It is a further object to provide novel cutter guide means for an electric dry sha-ver cutter head and which means positively prevents contact of the intended non engaging surfaces of the movable and the stationary cutters during operation of the shaver thereby substantially reducing the noise in the operation of the electric dry shaver.

The present invention contemplates novel cutter guide means for an electric dry shaver cutter head having an inner movable cutter and an outer stationary cutter and which guide means comprises an insert formed of a flexible plastic material disposed within the movable inner cutter. The insert is provided with pairs of spaced flexible leg portions which have foot portions engaging the inner sidewalls of the outer cutter positively preventing lateral movement of the inner cutter thereby reducing noise in g. the operation of the shaver and effecting linear movement of the inner cutter.

The above and other objects and advantages of the present invention will appear more fully hereinafter from a consideration of the detailed description which yfollows taken together with the accompanying drawings wherein one embodiment of the invention is illustrated.

In the drawing:

FIG. 1 is a fragmentary partly cross-sectional view of an electric dry shaver taken longitudinally through a cutter head having cutter head units embodying the present invention;

FIG. 2 is an end view of a cutter head of FIG. 1 removed from the yshaver casing with parts of one cutter head unit broken away;

FIG. 3 is a sectional view of one cutter head -unit taken on the line 3-3 of FIG. 2;

FIG. 4 is a perspective fragmentary end view of the ilCe cutter head unit with parts of the outer cutter broken away; and

FIG. 5 is a perspective fragmentary end view of the electric dry shaver shown in FIG. 1.

Referring now to the drawing for a more detailed description of the present invention and more particularly to FIG. 1, the reference numeral 10 indicates generally a fragmentary upper portion of a well known type shaver casing on which is mounted a cutter head 11. Cutter head 11 includes three individual and identical cutter head units 12 (FIG. 2) each of which is of the general type shown and described in U.S. Patent No. 2,793,430 to L. C. Carissimi dated May 28, 1957. Cutter head 11 is disposed on cutter head seats 13 (partially shown in FIG. l) formed on the upper portion of the casing 10 (FIG. l). A pair of clamps 14 one at each side of the upper portion of casing 10 have portions clamped to each side of the casing FIG. 5 and have upwardly extending lingers 15 which engage lips 16 provided on the cutter head 11 t0.

detachably mount the cutter head on the casing upon cutter head seats 13. A detachable casing section, usually referred to as a hair pocket, which section for the purposes of simplifying the drawing is not shown, is mounted over cutter head 11 and attached to the upper portion of the casing to provide a completed casing in a manner well known in the art.

Cutter head units 12 as illustrated yare of the reciprocatory type and are disposed in side by side relationship on a rectangular mounting plate 17 which mounting plate, as seen in FIG. 2, has surfaces inclined toward the middle thereof. Each cutter head unit 12 includes an elongated inverted U-shaped sheet metal outer cutter 18 having marginal portions of its opposite inner sidewalls 19 rigidly secured to the arms of an inverted U-shaped base spacer 20, for example by welding. Lugs or tabs 21 formed on each base spacer 20 are fitted in slots (not shown) in mounting plate 17 and then twisted to engage the underside of mounting plate 17 (FIG. l) to secure cutter head unit 12 to the mounting plate. An open ended elongated sheet metal inner cutter 22 substantially rectangular in transverse cross section (FIG. 2) is disposed within each outer cutter 13. Each inner cutter 22 is urged against its outer cutter 18 by a leaf spring 23 of the general type shown in the mentioned patent. A hook 24 on the free end of the arm 25 of leaf spring 23 is fitted into a slot 26 provided at one end of the bottom wall 27 of inner cutter 22. A T-shaped hook 28 on the free end of an arm 29 of leaf spring 23 is iitted into a key hole slot 30 at the opposite end of bottom wall 27 to detachably secure the leaf spring to the inner cutter 22. A looped portion 31 is formed intermediate arms 25 and 29 of leaf spring 23 and is disposed over an opening 32 (FIG. l) in base spacer 20 and which opening 32 registers with an opening 33 in mounting plate 17. Motor driven inner cutter drive arms 34 (FIG. l) of a well known type which are reciprocated by a motor (not shown) project through the aligned openings 32 and 33 in the cutter head 11 and engage the looped portion 31 of leaf spring 23 whereby leaf spring 23 urges inner cutter 22 into cutting cooperation with its outer cutter 1S (FIGS. l and 2).

Each inner cutter 22 is provided with a longitudinally extending reinforcing channel 35 intermediate its upper side edges (FIG. 2) and which channel 35 is disposed within a similar longitudinally extending channel 36 provided in the outer cutter I8. The top surface of the inner cutter FIGS. 2 and 4 on each side of the channels 35 and 36 engages the underside of the top of outer cutter 18 to clip hair that enters the aligned comb openings 39 of the cutter elements. Reasonable clearances are provided between the outer sidewalls 37 (FIG. 3) of the inner cutter 22 and the inner sidewalls 19 of the outer cutter to allow for reciprocation of the inner cutter and to l? permit the entry of hair into the cutter head during operation of the shaver. Similar clearances are provided between the U-shaped channel members 35 and 36 of the inner and outer cutters.

An elongated guide or insert member 4t) formed of a molded flexible plastic material having a low co-eiicient of friction, such as nylon or the like is disposed within each inner cutter 22 and rests upon and longitudinally of the bottom wall 27 of the inner cutter. The opposite ends of the insert 40 are each provided with a pair of flexible legs 41 and 42 and which legs have laterally extending foot portions 43. Foot portions 43 project through slots 44 provided at each lower corner of the spaced sidewalls 37 of the inner cutter. The rounded foot portions 43 bear against inner sidewalls 19 of router cutter 18. Spaced pairs of shoulder portions d and 46 are formed intermediate the ends of insert 4t) and which shoulder portions 45 and 46 bear against the inner sidewalls of inner cutter 22. It will be apparent that insert 40 due to the iiexible material from which it is formed, is easily inserted into position within inner cutter 22 from either open end of inner cutter 22.

In operationV of the shaver, oscillator arm 34 reciprocates inner cutter 22 within outer cutter 1S in the direction designated by the arrows A' and B shown in FIG. 3. Foot portions 43 of flexible legs 41 and 42 bear against inner sidewalls 19 of louter cutter 18 at all times to prevent lateral sidewise movement of inner cutter 22 from its path of linear reciprocating movement. Further due to necessary operating tolerances, a foot portion 43, will iiex its leg portion 4.1i, if necessary, to follow any variations in the clearance between the inner and louter cutters caused by changes in thickness or contour of the sidewalls 19 of outer cutter 22 and still bear against the :sidewalls 19 without exerting a force to impede the movement of the innerV cutter. Shoulder portions 45 and 46 bear against the inner sidewalls of inner cutter 22 and foot portions 43 engage the sidewalls of slots 44 in which they are inserted to positively prevent insert 40 from accidently leaving inner cutter 22.

It is apparent that the novel inner cutter guide means has many advantages in use. One advantage is that the surfaces of inner cutter 22 spaced from outer cutter 18 are prevented from contacting outer cutter 18 during reciprocation of inner cutter` 22 through foot portions 4,3 which bear against the outer cutter as above described. This arrangement reduces the amount of noise inherent in an electric dry shaver and unrestrained shifting of the inner cutter on drive arm 3.4 inthe direction of the sidewalls of the outer cutter is prevented. As a result linear movement of the inner cutter is attained.

It will be understood by those skilled in the art that the inner cutter guide means is adaptable to different types of cutter heads other than the reciprocatory type described above in detail. It is readilyl adaptable to a rotary type cutter head wherein the inner cutter rotates within the outer cutter. T he guide means is also adaptable to a cutter head wherein the outer cutter is moved relative to a stationary inner cutter.

Although one embodiment of the present invention has been illustrated and described in detail, it is to be eX- pressly understood that the invention is not limited thereto. Various changes can be made in the design and arrangement ofparts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed is:

1. A cutter head unit for an electric dry shaver, comprising (a) a stationary metal outer cutter,

(b) an inner cutter disposed for movement within said outer cutter,

(c) said inner cutter having portions thereof in cutting engagement with said outer cutter,

(d) an inner cutter guide member disposed within said inner cutter for movement therewith,

(e) a pair of flexible leg portions provided at each opposite end of said inner cutter guide member,

(f) a foot portion provided on each of said exible legs and extending from said inner cutter to bear against the sidewalls of said outer cutter to prevent shifting of said inner cutter from its path of movement.

2. A cutter head unit for an electric dry shaver, cornprising (a) an elongated U-shaped metal outer cutter,

(b) an elongated open ended metall inner cutter disposed for movement within said outer cutter,

(c) said inner cutter having portions thereof in cutting engagement with said outer cutter,

(d) an elongated inner cutter guide member inserted within said inner cutter,

(e) liexible leg portions provided on said guide member,

(f) foot portions on said flexible leg portions extending from said inner cutter to bear against the inner side walls of said outer cutter to prevent shifting of said inner cutter from its path of reciprocation.

3. The cutter head unit of claim 2 wherein the inner cutter guide member is provided with spaced shoulder portions formed intermediate the ends thereof which shoulder portions engage opposite inner sidewalls of the inner cutter to prevent dislodgement of said guide member from said inner cutter.

4. A cutter head unit for an electric dry shaver, comprising (a) a stationary outer cutter having inner wall portions,

(b) a movable inner cutter disposed within said outer cutter,

(c) said inner cutter having iirst outer Wall portions in cutting engagement with said outer cutter and second outer wall portions spaced from Isaid inner wall portions of said router cutter,

(d) means maintaining said inner cutter in cutting engagement with said outer cutter, and

(e) guide means to prevent lateral shifting of said inner cutter during movement of said inner cutter,

(f) said guide means comprising a guide member carried by a said inner cutter, and

(.g) spaced iiexible portions on said guide member extending from said inner cutter and biased into engagement with said inner Wall portions of said outer cutter to maintain said second outer wall p0rtions of said inner cutter spaced from said inner wall portions of said outer cutter during movement of said inner cutter,

(h) said flexible portions adapted to ilex in accordance with the contour of saidinner wall portions of said outer cutter to maintain said flexible portions in continuous engagement with. said outer cutter during said movement of said inner cutter.

5. A cutter head unit for an electric dry shaver, comprising (a) a stationary cutter,

(b) a movable. cutter disposed for movement in a predetermined path relative to said stationary cutter,

(c) said movable cutter having rst portions in cutting engagement with said stationary cutter and second portions spaced from and out of contact with said stationary cutter,

(d) means maintaining said first portions of said movableV cutter in cutting engagement with said stationary cutter, and

(e) guide means mounted on one of said cutters to prevent lateral shifting of said movable cutter from said path of movement,

(f) said guide means comprising a guide member,

(g.) a flexible portion on said guide member extending from. said one of said cutters and biased into constant engagement with the -other one of said cutters during movement :of said movable cutter to maintain said second portions of said movable cutter spaced from said stationary cutter,

5 6 (h) said engaged exible portion adapted to move References Cited bythe Examiner laterally in a direction towards said one cutter in ac- UNITED STATES PATENTS cordance with changes in the contour of said other cutter engaged by said flexible portion during said 2,273,685 2/42 Berg 30-43-92 movement of said movable cutter to thereby prevent 5 219161821 12/59 Winner 30*"415 shifting of said movable cutter from the path of I. movement and to prevent the contact of said second WHJLIAM FELDMAN P' "muy Exammer' portions of said movable cutter with said stationary MYRON C. KRUSE, Examiner. cutter. 

1. A CUTTER HEAD UNIT FOR AN ELECTRIC DRY SHAVER, COMPRISING (A) A STATIONARY METAL OUTER CUTTER, (B) AN INNER CUTTER DISPOSED FOR MOVEMENT WITHIN SAID OUTER CUTTER, (C) SAID INNER CUTTER HAVING PORTIONS THEREOF IN CUTTING ENGAGEMENT WITH SAID OUTER CUTTER, (D) AN INNER CUTTER GUIDE MEMBER DISPOSED WITHIN SAID INNER CUTTER FOR MOVEMENT THEREWITH, (E) A PAIR OF FLEXIBLE LEG PORTIONS PROVIDED AT EACH OPPOSITE END OF SAID INNER CUTTER GUIDE MEMBER, (F) A FOOT PORTION PROVIDED ON EACH OF SAID FLEXIBLE LEGS AND EXTENDING FROM SAID INNER CUTTER TO BEAR AGAINST THE SIDEWALLS OF SAID OUTER CUTTER TO PREVENT SHIFTING OF SAID INNER CUTTER FROM ITS PATH OF MOVEMENT. 